Configuring Optimized Roaming

Information About Optimized Roaming

Optimized roaming resolves the problem of sticky clients that remain associated to access points that are far away and outbound clients that attempt to connect to a Wi-Fi network without having a stable connection. This feature disassociates clients based on the RSSI of the client data packets and data rate. The client is disassociated if the RSSI alarm condition is met and the current data rate of the client is lower than the optimized roaming data rate threshold. You can disable the data rate option so that only RSSI is used for disassociating clients.

Optimized roaming also prevents client association when the client's RSSI is low. This feature checks the RSSI of the incoming client against the RSSI threshold. This check prevents the clients from connecting to a Wi-Fi network unless the client has a viable connection. In many scenarios, even though clients can hear beacons and connect to a Wi-Fi network, the signal might not be strong enough to support a stable connection.

You can also configure the client coverage reporting interval for a radio by using optimized roaming. The client coverage statistics include data packet RSSIs, Coverage Hole Detection and Mitigation (CHDM) pre-alarm failures, retransmission requests, and current data rates.

Optimized Roaming is implemented in the following scenarios:

  • Addresses the sticky client challenge by pro-actively disconnecting clients.

  • Actively monitors Data RSSI packets.

  • Disassociates client when the RSSI is lower than the set threshold.

Restrictions for Optimized Roaming

  • You cannot configure the optimized roaming interval until you disable the 802.11a/b network.

Configuring Optimized Roaming (GUI)

Procedure
    Step 1   Choose Wireless > Advanced > Optimized Roaming. The Optimized Roaming page is displayed.

    Step 2   To enable optimized roaming for an 802.11 band, check the Enable check box.

    You can configure the optimized roaming interval and data rate threshold values only after you enable optimized roaming for an 802.11 band.

    Step 3   In the Optimized Roaming Interval text box, enter a value for the interval at which an access point reports the client coverage statistics to the controller.

    The client coverage statistics include data packet RSSIs, Coverage Hole Detection and Mitigation (CHDM) pre-alarm failures, retransmission requests, and current data rates. The range is from 5 to 90 seconds. The default value is 90 seconds.

    Note   

    You must disable the 802.11a/b network before you configure the optimized roaming reporting interval. If you configure a low value for the reporting interval, the network can get overloaded with coverage report messages.

    Step 4   In the Optimized Roaming Data Rate Threshold text box, enter a value for the threshold data rate of the client.
    The following data rates are available:

    • 802.11a—6, 9, 12, 18, 24, 36, 48, and 54.

    • 802.11b—1, 2, 5.5, 11, 6, 9, 12, 18, 24, 36, 48, and 54.

    Optimized roaming disassociates clients based on the RSSI of the client data packet and data rate. The client is disassociated if the current data rate of the client is lower than the Optimized Roaming Data Rate Threshold.

    What to Do Next

    Optimized roaming checks the client RSSI at the time of an association. This RSSI value is verified against the configured CHDM RSSI with a 6 db hysteresis. To verify the RSSI threshold configured for coverage hole detection, choose Wireless > 802.11a/n/ac or 802.11b/g/n > RRM > Coverage to open the 802.11a/ac (or 802.11b/g/n) > RRM > Coverage page.

    Configuring Optimized Roaming (CLI)

    Procedure
      Step 1   Enable or disable optimized roaming by entering this command:

      config advanced {802.11a | 802.11b} optimized-roaming {enable | disable}

      By default, optimized roaming is disabled.

      Step 2   Configure the client coverage reporting interval for 802.11a/b networks by entering this command:

      config advanced {802.11a | 802.11b} optimized-roaming interval seconds

      The range is from 5 to 90 seconds. The default value is 90 seconds.

      Note   

      You must disable the 802.11a/b network before you configure the optimized roaming reporting interval.

      Step 3   Configure the threshold data rate for 802.11a/b networks by entering this command:

      config advanced {802.11a | 802.11b} optimized-roaming datarate mbps

      For 802.11a, the configurable data rates are 6, 9, 12, 18, 24, 36, 48, and 54. For 802.11b, the configurable data rates are 1, 2, 5.5, 11, 6, 9, 12, 18, 24, 36, 48, and 54. You can configure 0 to disable the data rate.

      Step 4   View information about optimized roaming for each band by entering this command:

      show advanced {802.11a | 802.11b} optimized-roaming 

      (Cisco Controller) > show advanced 802.11a optimized-roaming
OptimizedRoaming
  802.11a OptimizedRoaming Mode.................. Enabled
  802.11a OptimizedRoaming Reporting Interval.... 20 seconds
  802.11a OptimizedRoaming Rate Threshold........ disabled
      Step 5   View information about optimized roaming statistics by entering this command:

      show advanced {802.11a | 802.11b} optimized-roaming stats 

      (Cisco Controller) > show advanced 802.11a optimized-roaming stats
OptimizedRoaming Stats
  802.11a OptimizedRoaming Disassociations....... 0
  802.11a OptimizedRoaming Rejections............ 0